a. Field of the Invention
This invention relates to a flat knitting machine provided with compound needles which makes it possible, when it becomes necessary to produce an empty needle in needles being used for knitting while knitting is performed using the flat knitting machine, to make an empty needle by holding a loop held on the needle to another needle, a transfer jack or some other member.
b. Description of Related Art
A usual flat knitting machine is formed as a so-called two-bed flat knitting machine wherein a pair of needle beds on each of which a large number of needles are provided in a row are disposed forwardly and rearwardly on the opposite sides of a needle bed gap. A flat knitting machine of the type mentioned is constructed such that the needles on the needle beds are used to knit stitch loops and the stitch loops formed on each of the needle beds can be transferred to the opposing needles of the other needle bed, and can knit various knit fabrics by combinations of stitch formation and transfer of loops.
As needles for use with a flat knitting machine, latch needles and compound needles are available. It is known that employment of compound needles allows a knitting machine to be formed with a reduced size since the back and forth stroke of a needle can be reduced to approximately one half when compared with conventional latch needles because the slider and the needle body of a compound needle are moved relative to each other to open and close the hook, and this results in augmentation of the productivity. Various types of compound needles have been developed till now.
Upon knitting of a knit fabric, for example, if only the needles on the front needle bed are used for knitting, then a knit fabric of a plain stitch structure (knit stitches) is knitted, but if a yarn is supplied in a zigzag pattern to the needles of the front and back needle beds, then a knit fabric of a rib (rib) stitch structure is knitted.
On the other hand, if circulating knitting is performed such that a yarn is first supplied to the needles of the front needle bed and then supplied to the needles of the back needle bed continuously, then a tubular knit fabric composed of a front side knit fabric and a back side knit fabric are joined to each other at the opposite ends hereof is knitted.
In order to perform knitting with knit stitches and purl stitches included in a mixed condition in the same wale or to perform such knitting such that a stitch loop is moved and overlapped with an adjacent stitch loop, an empty needle on the opposing needle bed is used. For example, in order to knit a links-and-links pattern as a pattern which includes knit stitches and purl stitches in a mixed condition, stitch loops are first formed on the front needle bed and then the stitch needles are transferred to the needles of the opposing back needle bed and then stitch loops of the following course are formed on the back needle bed, and in the succeeding knitting, stitch loops are successively transferred back and forth alternately between the two beds to knit the succeeding sources. On the other hand, in order to knit a texture pattern or perform full-fashioned knitting, stitch loops are first transferred to empty needles of the other needle bed, and then the needle beds are racked relative each other, whereafter the transferred stitch loops are transferred to adjacent needles to the needles of the original needle bed so that they are overlapped with stitch loops of the adjacent needles.
In order to knit a knit fabric of a plain stitch, a wide rib stitch or the like, the opposing needles should be used because they are empty needles. However, in knitting of a 1.times.1 rib stitch fabric or a tubular knit fabric which is knitted using all of the needles of the front-t and back needle beds, it is impossible to such knitting as described above because empty needles to which stitch loops should be transferred cannot be assured. In this instance, such a countermeasure must be taken to use a flat knitting machine of the type which includes, in addition to a pair of front and back needle beds, an auxiliary bed (transfer jack bed) which accommodates transfer jacks as knitting members for exclusive use for loop transfer or a so-called four-bed flat knitting machine which includes another pair of needle beds provided above front and rear needle beds to obtain empty needles.
In this manner, conventionally it is an essential requirement that, in order to transfer stitch loops between needle beds, empty needles be present on the other needle bed, and, where a knit fabric for which empty needles cannot be assured is knitted, the requirement has been, as a fixed idea, a significant restriction to development of the variety of knitting of knit fabrics. This follows that, when another stitch loop is transferred to a needle on which a stitch loop is held, the two stitch loops form a double stitch and cannot be separated from each other any more, and consequently, also such a transfer jack bed or a four-bed flat knitting machine as described above is subject to the common problem to that of a two-bed flat knitting machine.